Module 3 - Transport in animals Flashcards
what is a double system?
Blood vessels twice through the heart for each circuit of the body.
what is a closed system?
The blood is enclosed in blood vessels and does not come directly in contact with the cells of the body.
what are the feature of a closed circulatory system?
- Blood enclosed in the vessels
- Heart pumps in the blood around the body under pressure quickly and returns to the heart
- substances enter the body by diffusion through the walls of the blood vessels.
where are single closed circulatory systems found in?
number of groups including fish and annelid worms
what do single closed circulatory system transport?
Transports blood through a single circuit where blood is pumped by the heart to the gills for oxygenation
what are the key features of a single closed circulatory system?
- blood passes through two sets of capillaries before it returns back to the heart.
- first capillaries - exchange oxygen and CO2.
- second capillaries - substances are exchanged between the blood and cell
- blood pressure drops in the system so blood returns to the cell slowly
what do the first capillaries exchange in a single closed circulatory system?
exchange oxygen and CO2.
what do the second capillaries exchange in a single closed circulatory system?
substances are exchanged between the blood and cell
where are open circulatory systems found?
found in mainly invertebrate animals including insects and some molluscs
What are the key features of a open circulatory systems ?
- few vessels to contain the transport medium
- pumped straight from the heart into the body cavity of an animal
- transports medium returns to the heart through an open ended vessel
what do open circulatory systems transport?
- food and nitrogenous waste products and the cells involved in deference against disease
what do open circulatory systems not transport?
Oxygen or carbon dioxide
where are double closed circulatory systems found in?
found in ventricles in the heart
what do double closed circulatory systems transport?
- deoxyenated blood to the lungs
- oxygenated blood to the body
what are the key features of a double closed circulatory systems?
- transports substances around the body
- involved in two separate circulations
- blood is pumped from the heart to the lungs to pick up oxygen and unload carbon dioxide
- blood flow through the heart is pumped out to travel all around the body and return to the heart
what is the cardiac cycle?
a complete sequence of relaxation and contractions
what is an heart beat?
- the sounds made by blood pressure closing the heart valves
what are the 3 stages of the cardiac cycle?
- Diastole
- ventricular diastole
- atrial systole
what happens in Diastole?
- Relaxation of the atria and ventricles
- Volume increases
-pressure decreases
what happens in ventricular systole?
- Contraction forces blood out to the lungs and the body
- volume decreases
- pressure increases
what happens in atrial systole?
- Ventricles contract and push blood out of the aorta and pulmonary artery
Formula for cardiac output?
Cardiac output (cm3 min-1) = Heart rate (BPM) x stroke volume (cm^3)
what does it mean the heart muscle is myogenic?
Creates its only electrical impulses and not just reliant on the nervous system
What is intrinsic rhymicity?
The ability for cells to beat together.
where is the cardiovascular centre?
In the brain
what is the cardiovascular centre?
controls if the body requirements changed the heart needs to speed up or slow down controlled by nerves
How is the heart beat controlled?
- specialised cells in the SAN control action potential around 70 times each minute
- the membrane around the node, allows a charge to be maintained across the membrane
- at rest the node is polarised
- when contraction occurs the node is polarised
- positively charged ions move into the node stimulating the production of an electrical impulse
what does it mean the node is polarised?
- the cells inside the node are negatively charged in comparison to the outside.
what does an ECG stand for?
Electro cardio graph
What is an ECG used for?
To check and monitor the electrical activity of the heart
What is a p wave?
The electrical activity during the atrial systole
what is a QRS complex?
Electrical activity during ventrical systole
what is a T wave?
ventricular repolarisation - recovery of ventricular walls
what is Tissue fluid?
- The liquid that surrounds the cells in a capillary bed
- It is the medium through which oxygen and carbon dioxide are exchanged between the blood and respiring cells
where is Tissue fluid formed?
It is formed at the arterial end of the capillary beds and reabsorbed at the venous end
what is hydrostatic pressure?
It is the pressure exerted by the blood pushing against the vessel wall
How is hydrostatic pressure created?
Created by the contraction of the muscular walls of the ventricles during ventricular systole
what is hydrostatic pressure measured in?
millimeters of mercury (mm Hg)
what is oncotic pressure?
- Blood contains large amounts of dissolved proteins called plasma proteins
- oncotic pressure is the pressure f proteins pulling water towards them
what is the main type of plasma protein called?
- albumins
what is the function of albumins?
- Its function is to create oncotic pressure
Does the arterial blood have erythrocytes?
Yes, many
Does the arterial blood have white blood cells
- yes
- Lymphocytes and neutrophills